CatStation/Content.Shared/NodeContainer/Node.cs

using Content.Shared.NodeContainer.NodeGroups;
using Robust.Shared.Map.Components;

namespace Content.Shared.NodeContainer;

/// <summary>
///     Organizes themselves into distinct <see cref="INodeGroup"/>s with other <see cref="Node"/>s
///     that they can "reach" and have the same <see cref="Node.NodeGroupID"/>.
/// </summary>
[ImplicitDataDefinitionForInheritors]
public abstract partial class Node
{
    /// <summary>
    ///     An ID used as a criteria for combining into groups. Determines which <see cref="INodeGroup"/>
    ///     implementation is used as a group, detailed in <see cref="INodeGroupFactory"/>.
    /// </summary>
    [DataField("nodeGroupID")]
    public NodeGroupID NodeGroupID { get; private set; } = NodeGroupID.Default;

    /// <summary>
    ///     The node group this node is a part of.
    /// </summary>
    [ViewVariables] public INodeGroup? NodeGroup;

    /// <summary>
    ///     The entity that owns this node via its <see cref="NodeContainerComponent"/>.
    /// </summary>
    [ViewVariables] public EntityUid Owner { get; private set; } = default!;

    /// <summary>
    ///     If this node should be considered for connection by other nodes.
    /// </summary>
    public virtual bool Connectable(IEntityManager entMan, TransformComponent? xform = null)
    {
        if (Deleting)
            return false;

        if (entMan.IsQueuedForDeletion(Owner))
            return false;

        if (!NeedAnchored)
            return true;

        xform ??= entMan.GetComponent<TransformComponent>(Owner);
        return xform.Anchored;
    }

    [DataField]
    public bool NeedAnchored { get; private set; } = true;

    public virtual void OnAnchorStateChanged(IEntityManager entityManager, bool anchored) { }

    /// <summary>
    ///    Prevents a node from being used by other nodes while midway through removal.
    /// </summary>
    public bool Deleting;

    /// <summary>
    ///     All compatible nodes that are reachable by this node.
    ///     Effectively, active connections out of this node.
    /// </summary>
    public readonly HashSet<Node> ReachableNodes = new();

    public int FloodGen;
    public int UndirectGen;
    public bool FlaggedForFlood;
    public int NetId;

    /// <summary>
    ///     Name of this node on the owning <see cref="NodeContainerComponent"/>.
    /// </summary>
    public string Name = default!;

    /// <summary>
    ///     Invoked when the owning <see cref="NodeContainerComponent"/> is initialized.
    /// </summary>
    /// <param name="owner">The owning entity.</param>
    public virtual void Initialize(EntityUid owner, IEntityManager entMan)
    {
        Owner = owner;
    }

    /// <summary>
    ///     How this node will attempt to find other reachable <see cref="Node"/>s to group with.
    ///     Returns a set of <see cref="Node"/>s to consider grouping with. Should not return this current <see cref="Node"/>.
    /// </summary>
    /// <remarks>
    /// <para>
    /// The set of nodes returned can be asymmetrical
    /// (meaning that it can return other nodes whose <see cref="GetReachableNodes"/> does not return this node).
    /// If this is used, creation of a new node may not correctly merge networks unless both sides
    /// of this asymmetric relation are made to manually update with <see cref="NodeGroupSystem.QueueReflood"/>.
    /// </para>
    /// </remarks>
    public abstract IEnumerable<Node> GetReachableNodes(TransformComponent xform,
        EntityQuery<NodeContainerComponent> nodeQuery,
        EntityQuery<TransformComponent> xformQuery,
        MapGridComponent? grid,
        IEntityManager entMan);
}